I'm a lousy two-fingered typist and a terrible speller. One of many things I like about Safari, which I use on my Macs at home, is the built-in spell checker. I still use Internet Explorer at work, however, because I don't like the appearance of Safari for Windows. Unfortunately, IE7 lacks a built-in spell checker.
I recently discovered IE7Pro, a free downloadable suite of add-ins for IE. "IE7Pro includes Tabbed Browsing Management, Spell Check, Inline Search, Super Drag Drop, Crash Recovery, Proxy Switcher, Mouse Gesture, Tab History Browser, Web Accelerator, User Agent Switcher, Webpage Capturer, AD Blocker, Flash Block, Greasemonkey like User Scripts platform, User Plug-ins, MiniDM, Google sponsored search,IE Faster and many more power packed features." At the moment, the only one I want is the spell checker, and I can customize the program so it is the only add-in that is functional.
I've been very happy with this product and recommend it. (Note to the FTC: This is not an endorsement because I got nothing from IE7Pro for making this recommendation.)